drivers/xen/events/events_fifo.c uses rmb() to communicate with the
other side.
For guests compiled with CONFIG_SMP, smp_rmb would be sufficient, so
rmb() here is only needed if a non-SMP guest runs on an SMP host.
Switch to the virt_rmb barrier which serves this exact purpose.
Pull in asm/barrier.h here to make sure the file is self-contained.
Suggested-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
When a CPU is offlined, there may be unprocessed events on a port for
that CPU. If the port is subsequently reused on a different CPU, it
could be in an unexpected state with the link bit set, resulting in
interrupts being missed. Fix this by consuming any unprocessed events
for a particular CPU when that CPU dies.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Cc: <stable@vger.kernel.org> # 3.14+
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
After commit 8c058b0b9c ("x86/irq: Probe for PIC presence before
allocating descs for legacy IRQs") early_irq_init() will no longer
preallocate descriptors for legacy interrupts if PIC does not
exist, which is the case for Xen PV guests.
Therefore we may need to allocate those descriptors ourselves.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Only use the first 4KB of the page to store the events channel info. It
means that we will waste 60KB every time we allocate page for:
* control block: a page is allocating per CPU
* event array: a page is allocating everytime we need to expand it
I think we can reduce the memory waste for the 2 areas by:
* control block: sharing between multiple vCPUs. Although it will
require some bookkeeping in order to not free the page when the CPU
goes offline and the other CPUs sharing the page still there
* event array: always extend the array event by 64K (i.e 16 4K
chunk). That would require more care when we fail to expand the
event channel.
Signed-off-by: Julien Grall <julien.grall@citrix.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
- Use the correct GFN/BFN terms more consistently.
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Merge tag 'for-linus-4.3-rc0b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen terminology fixes from David Vrabel:
"Use the correct GFN/BFN terms more consistently"
* tag 'for-linus-4.3-rc0b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/xenbus: Rename the variable xen_store_mfn to xen_store_gfn
xen/privcmd: Further s/MFN/GFN/ clean-up
hvc/xen: Further s/MFN/GFN clean-up
video/xen-fbfront: Further s/MFN/GFN clean-up
xen/tmem: Use xen_page_to_gfn rather than pfn_to_gfn
xen: Use correctly the Xen memory terminologies
arm/xen: implement correctly pfn_to_mfn
xen: Make clear that swiotlb and biomerge are dealing with DMA address
- Convert xen-blkfront to the multiqueue API
- [arm] Support binding event channels to different VCPUs.
- [x86] Support > 512 GiB in a PV guests (off by default as such a
guest cannot be migrated with the current toolstack).
- [x86] PMU support for PV dom0 (limited support for using perf with
Xen and other guests).
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Merge tag 'for-linus-4.3-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen updates from David Vrabel:
"Xen features and fixes for 4.3:
- Convert xen-blkfront to the multiqueue API
- [arm] Support binding event channels to different VCPUs.
- [x86] Support > 512 GiB in a PV guests (off by default as such a
guest cannot be migrated with the current toolstack).
- [x86] PMU support for PV dom0 (limited support for using perf with
Xen and other guests)"
* tag 'for-linus-4.3-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (33 commits)
xen: switch extra memory accounting to use pfns
xen: limit memory to architectural maximum
xen: avoid another early crash of memory limited dom0
xen: avoid early crash of memory limited dom0
arm/xen: Remove helpers which are PV specific
xen/x86: Don't try to set PCE bit in CR4
xen/PMU: PMU emulation code
xen/PMU: Intercept PMU-related MSR and APIC accesses
xen/PMU: Describe vendor-specific PMU registers
xen/PMU: Initialization code for Xen PMU
xen/PMU: Sysfs interface for setting Xen PMU mode
xen: xensyms support
xen: remove no longer needed p2m.h
xen: allow more than 512 GB of RAM for 64 bit pv-domains
xen: move p2m list if conflicting with e820 map
xen: add explicit memblock_reserve() calls for special pages
mm: provide early_memremap_ro to establish read-only mapping
xen: check for initrd conflicting with e820 map
xen: check pre-allocated page tables for conflict with memory map
xen: check for kernel memory conflicting with memory layout
...
Based on include/xen/mm.h [1], Linux is mistakenly using MFN when GFN
is meant, I suspect this is because the first support for Xen was for
PV. This resulted in some misimplementation of helpers on ARM and
confused developers about the expected behavior.
For instance, with pfn_to_mfn, we expect to get an MFN based on the name.
Although, if we look at the implementation on x86, it's returning a GFN.
For clarity and avoid new confusion, replace any reference to mfn with
gfn in any helpers used by PV drivers. The x86 code will still keep some
reference of pfn_to_mfn which may be used by all kind of guests
No changes as been made in the hypercall field, even
though they may be invalid, in order to keep the same as the defintion
in xen repo.
Note that page_to_mfn has been renamed to xen_page_to_gfn to avoid a
name to close to the KVM function gfn_to_page.
Take also the opportunity to simplify simple construction such
as pfn_to_mfn(page_to_pfn(page)) into xen_page_to_gfn. More complex clean up
will come in follow-up patches.
[1] http://xenbits.xen.org/gitweb/?p=xen.git;a=commitdiff;h=e758ed14f390342513405dd766e874934573e6cb
Signed-off-by: Julien Grall <julien.grall@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Currently, the event channel rebind code is gated with the presence of
the vector callback.
The virtual interrupt controller on ARM has the concept of per-CPU
interrupt (PPI) which allow us to support per-VCPU event channel.
Therefore there is no need of vector callback for ARM.
Xen is already using a free PPI to notify the guest VCPU of an event.
Furthermore, the xen code initialization in Linux (see
arch/arm/xen/enlighten.c) is requesting correctly a per-CPU IRQ.
Introduce new helper xen_support_evtchn_rebind to allow architecture
decide whether rebind an event is support or not. It will always return
true on ARM and keep the same behavior on x86.
This is also allow us to drop the usage of xen_have_vector_callback
entirely in the ARM code.
Signed-off-by: Julien Grall <julien.grall@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
This reverts commit fcdf31a7c1.
This was causing a WARNING whenever a PIRQ was closed since
shutdown_pirq() is called with irqs disabled.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: <stable@vger.kernel.org>
An event channel bound to a CPU that was offlined may still be linked
on that CPU's queue. If this event channel is closed and reused,
subsequent events will be lost because the event channel is never
unlinked and thus cannot be linked onto the correct queue.
When a channel is closed and the event is still linked into a queue,
ensure that it is unlinked before completing.
If the CPU to which the event channel bound is online, spin until the
event is handled by that CPU. If that CPU is offline, it can't handle
the event, so clear the event queue during the close, dropping the
events.
This fixes the missing interrupts (and subsequent disk stalls etc.)
when offlining a CPU.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
This is a preparatory patch for moving irq_data struct members.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Using xen/page.h will be necessary later for using common xen page
helpers.
As xen/page.h already include asm/xen/page.h, always use the later.
Signed-off-by: Julien Grall <julien.grall@citrix.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: netdev@vger.kernel.org
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
A non-percpu VIRQ (e.g., VIRQ_CONSOLE) may be freed on a different
VCPU than it is bound to. This can result in a race between
handle_percpu_irq() and removing the action in __free_irq() because
handle_percpu_irq() does not take desc->lock. The interrupt handler
sees a NULL action and oopses.
Only use the percpu chip/handler for per-CPU VIRQs (like VIRQ_TIMER).
# cat /proc/interrupts | grep virq
40: 87246 0 xen-percpu-virq timer0
44: 0 0 xen-percpu-virq debug0
47: 0 20995 xen-percpu-virq timer1
51: 0 0 xen-percpu-virq debug1
69: 0 0 xen-dyn-virq xen-pcpu
74: 0 0 xen-dyn-virq mce
75: 29 0 xen-dyn-virq hvc_console
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: <stable@vger.kernel.org>
.. because bind_evtchn_to_cpu(evtchn, cpu) will map evtchn to
'info' and pass 'info' down to xen_evtchn_port_bind_to_cpu().
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Tested-by: Annie Li <annie.li@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
When a guest is resumed, the hypervisor may change event channel
assignments. If this happens and the guest uses 2-level events it
is possible for the interrupt to be claimed by wrong VCPU since
cpu_evtchn_mask bits may be stale. This can happen even though
evtchn_2l_bind_to_cpu() attempts to clear old bits: irq_info that
is passed in is not necessarily the original one (from pre-migration
times) but instead is freshly allocated during resume and so any
information about which CPU the channel was bound to is lost.
Thus we should clear the mask during resume.
We also need to make sure that bits for xenstore and console channels
are set when these two subsystems are resumed. While rebind_evtchn_irq()
(which is invoked for both of them on a resume) calls irq_set_affinity(),
the latter will in fact postpone setting affinity until handling the
interrupt. But because cpu_evtchn_mask will have bits for these two
cleared we won't be able to take the interrupt.
With that in mind, we need to bind those two channels explicitly in
rebind_evtchn_irq(). We will keep irq_set_affinity() so that we have a
pass through generic irq affinity code later, in case something needs
to be updated there as well.
(Also replace cpumask_of(0) with cpumask_of(info->cpu) in
rebind_evtchn_irq(): it should be set to zero in preceding
xen_irq_info_evtchn_setup().)
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reported-by: Annie Li <annie.li@oracle.com>
Cc: <stable@vger.kernel.org> # 3.14+
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Using the pvops kernel a NULL pointer dereference was detected on a
large machine (144 processors) when booting as dom0 in
evtchn_fifo_unmask() during assignment of a pirq.
The event channel in question was the first to need a new entry in
event_array[] in events_fifo.c. Unfortunately xen_irq_info_pirq_setup()
is called with evtchn being 0 for a new pirq and the real event channel
number is assigned to the pirq only during __startup_pirq().
It is mandatory to call xen_evtchn_port_setup() after assigning the
event channel number to the pirq to make sure all memory needed for the
event channel is allocated.
Signed-off-by: Juergen Gross <jgross@suse.com>
Cc: <stable@vger.kernel.org> # 3.14+
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Since 05a812ac47 (xen/events/fifo:
correctly align bitops), ready is an unsigned long instead of uint32_t
and the BM() macro is no longer required.
Signed-off-by: Frediano Ziglio <frediano.ziglio@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
When using the FIFO-based ABI on x86_64, if the last port is at the
end of an event array page then sync_test_bit() on this port's event
word will read beyond the end of the page and in certain circumstances
this may fault.
The fault requires the following page in the kernel's direct mapping
to be not present, which would mean:
a) the array page is the last page of RAM; or
b) the following page is ballooned out /and/ it has been used for a
foreign mapping by a kernel driver (such as netback or blkback)
/and/ the grant has been unmapped.
Use the infrastructure added for arm64 to ensure that all bitops
operating on event words are unsigned long aligned.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: stable@vger.kernel.org
When using the FIFO-based event channel ABI, if the control block or
the local HEADs are not reset after resuming the guest may see stale
HEAD values and will fail to traverse the FIFO correctly.
This may prevent one or more VCPUs from receiving any events following
a resume.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: stable@vger.kernel.org
Pull core irq updates from Thomas Gleixner:
"The irq department delivers:
- Another tree wide update to get rid of the horrible create_irq
interface along with its even more horrible variants. That also
gets rid of the last leftovers of the initial sparse irq hackery.
arch/driver specific changes have been either acked or ignored.
- A fix for the spurious interrupt detection logic with threaded
interrupts.
- A new ARM SoC interrupt controller
- The usual pile of fixes and improvements all over the place"
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
Documentation: brcmstb-l2: Add Broadcom STB Level-2 interrupt controller binding
irqchip: brcmstb-l2: Add Broadcom Set Top Box Level-2 interrupt controller
genirq: Improve documentation to match current implementation
ARM: iop13xx: fix msi support with sparse IRQ
genirq: Provide !SMP stub for irq_set_affinity_notifier()
irqchip: armada-370-xp: Move the devicetree binding documentation
irqchip: gic: Use mask field in GICC_IAR
genirq: Remove dynamic_irq mess
ia64: Use irq_init_desc
genirq: Replace dynamic_irq_init/cleanup
genirq: Remove irq_reserve_irq[s]
genirq: Replace reserve_irqs in core code
s390: Avoid call to irq_reserve_irqs()
s390: Remove pointless arch_show_interrupts()
s390: pci: Check return value of alloc_irq_desc() proper
sh: intc: Remove pointless irq_reserve_irqs() invocation
x86, irq: Remove pointless irq_reserve_irqs() call
genirq: Make create/destroy_irq() ia64 private
tile: Use SPARSE_IRQ
tile: pci: Use irq_alloc/free_hwirq()
...
No need to expose this outside of the ioapic code. The dynamic
allocations are guaranteed not to happen in the gsi space. See commit
62a08ae2a.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Grant Likely <grant.likely@linaro.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: x86@kernel.org
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20140507154335.959870037@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
FIFO event channels require bitops on 32-bit aligned values (the event
words). Linux's bitops require unsigned long alignment which may be
64-bits.
On arm64 an incorrectly unaligned access will fault.
Fix this by aligning the bitops along with an adjustment for bit
position and using an unsigned long for the local copy of the ready
word.
Cc: stable@vger.kernel.org
Signed-off-by: Vladimir Murzin <murzin.v@gmail.com>
Tested-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
Reviewed-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Patch 99c8b79d3c "xen: Add proper irq accounting for HYPERCALL vector"
added a call to inc_irq_stat(irq_hv_callback_count) in common Xen code,
however both the inc_irq_stat function and the irq_hv_callback_count
counter are architecture specific.
This makes the code build again on ARM by moving the call into the
existing #ifdef CONFIG_X86. We may want to later do the same implementation
on ARM that x86 has though.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Xen <xen-devel@lists.xenproject.org>
Add support for MSI message groups for Xen Dom0 using the
MAP_PIRQ_TYPE_MULTI_MSI pirq map type.
In order to keep track of which pirq is the first one in the group all
pirqs in the MSI group except for the first one have the newly
introduced PIRQ_MSI_GROUP flag set. This prevents calling
PHYSDEVOP_unmap_pirq on them, since the unmap must be done with the
first pirq in the group.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
The user space interface does not filter out offline cpus. It merily
verifies that the mask contains at least one online cpu. So the
selector in the irq chip implementation needs to make sure to pick
only an online cpu because otherwise:
Offline Core 1
Set affinity to 0xe
Selector will pick first set bit, i.e. core 1
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Xen <xen-devel@lists.xenproject.org>
Link: http://lkml.kernel.org/r/20140304203100.978031089@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Warn if any PIRQ cannot be bound to an event channel. Remove the check
for irq_desc->action. This hypercall never fails in practice so we can
emit a warning unconditionally.
Remove a check for a valid irq desc. The only caller of
xen_destroy_irq() will only do so if the irq was previously fully
setup, which means the descriptor has been allocated as well.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Xen <xen-devel@lists.xenproject.org>
Cc: David Vrabel <david.vrabel@citrix.com>
Link: http://lkml.kernel.org/r/20140223212738.579581220@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
generic_handler_irq() already tests for !desc so use this instead of
generic_handle_irq_desc().
Use irq_get_irq_data() instead of desc->irq_data.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Xen <xen-devel@lists.xenproject.org>
Link: http://lkml.kernel.org/r/20140223212738.222412125@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Since bind_evtchn_to_cpu() is always called after an event channel is
bound, there is no need to call it after closing an event channel.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
resend_irq_on_evtchn() was only used by ia64 (which no longer has Xen
support).
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Commit fc087e1073 (xen/events: remove
unnecessary init_evtchn_cpu_bindings()) causes a regression.
The kernel-side VCPU binding was not being correctly set for newly
allocated or bound interdomain events. In ARM guests where 2-level
events were used, this would result in no interdomain events being
handled because the kernel-side VCPU masks would all be clear.
x86 guests would work because the irq affinity was set during irq
setup and this would set the correct kernel-side VCPU binding.
Fix this by properly initializing the kernel-side VCPU binding in
bind_evtchn_to_irq().
Reported-and-tested-by: Julien Grall <julien.grall@linaro.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Commit 1fe565517b ("xen/events: use
the FIFO-based ABI if available") added new instances of __cpuinit
macro usage.
We removed this a couple versions ago; we now want to remove
the compat no-op stubs. Introducing new users is not what
we want to see at this point in time, as it will break once
the stubs are gone.
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Fix to return -ENOMEM from the error handling case instead of
0 (overwrited to 0 by the HYPERVISOR_event_channel_op call),
otherwise the error condition cann't be reflected from the
return value.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
PVH is a PV guest with a twist - there are certain things
that work in it like HVM and some like PV. There is
a similar mode - PVHVM where we run in HVM mode with
PV code enabled - and this patch explores that.
The most notable PV interfaces are the XenBus and event channels.
We will piggyback on how the event channel mechanism is
used in PVHVM - that is we want the normal native IRQ mechanism
and we will install a vector (hvm callback) for which we
will call the event channel mechanism.
This means that from a pvops perspective, we can use
native_irq_ops instead of the Xen PV specific. Albeit in the
future we could support pirq_eoi_map. But that is
a feature request that can be shared with PVHVM.
Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Implement all the event channel port ops for the FIFO-based ABI.
If the hypervisor supports the FIFO-based ABI, enable it by
initializing the control block for the boot VCPU and subsequent VCPUs
as they are brought up and on resume. The event array is expanded as
required when event ports are setup.
The 'xen.fifo_events=0' command line option may be used to disable use
of the FIFO-based ABI.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Add xen_irq_set_priority() to set an event channels priority. This function
will only work with event channel ABIs that support priority (i.e., the
FIFO-based ABI).
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Add the hypercall sub-ops and the structures for the shared data used
in the FIFO-based event channel ABI.
The design document for this new ABI is available here:
http://xenbits.xen.org/people/dvrabel/event-channels-H.pdf
In summary, events are reported using a per-domain shared event array
of event words. Each event word has PENDING, LINKED and MASKED bits
and a LINK field for pointing to the next event in the event queue.
There are 16 event queues (with different priorities) per-VCPU.
Key advantages of this new ABI include:
- Support for over 100,000 events (2^17).
- 16 different event priorities.
- Improved fairness in event latency through the use of FIFOs.
The ABI is available in Xen 4.4 and later.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Remove the check during unbind for NR_EVENT_CHANNELS as this limits
support to less than 4096 ports.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Refactor static array evtchn_to_irq array to be dynamically allocated by
implementing get and set functions for accesses to the array.
Two new port ops are added: max_channels (maximum supported number of
event channels) and nr_channels (number of currently usable event
channels). For the 2-level ABI, these numbers are both the same as
the shared data structure is a fixed size. For the FIFO ABI, these
will be different as the event array is expanded dynamically.
This allows more than 65000 event channels so an unsigned short is no
longer sufficient for an event channel port number and unsigned int is
used instead.
Signed-off-by: Malcolm Crossley <malcolm.crossley@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Add a hook for port-specific setup and call it from
xen_irq_info_common_setup().
The FIFO-based ABIs may need to perform additional setup (expanding
the event array) before a bound event channel can start to receive
events.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
The FIFO-based event ABI requires additional setup of newly bound
events (it may need to expand the event array) and this setup may
fail.
xen_irq_info_common_init() is a useful place to put this setup so
allow this call to fail. This call and the other similar calls are
renamed to be *_setup() to reflect that they may now fail.
This failure can only occur with new event channels not on rebind.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
evtchn_ops contains the low-level operations that access the shared
data structures. This allows alternate ABIs to be supported.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
In preparation for alternative event channel ABIs, move all the
functions accessing the shared data structures into their own file.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
events.c will be split into multiple files so move it into its own
directory.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
